With the Zika virus spreading rapidly through the Western Hemisphere, particularly in South America, the world has begun to worry about how the virus will affect this summer’s Olympics.

Two weeks after the Australian Olympic Committee warned pregnant women to avoid traveling to Rio de Janeiro, home of the 2016 Games, the U.S. Olympic committee has expressed its own concerns, according to Reuters. The USOC reportedly told sports federations and athletes that anyone concerned about contracting the Zika virus should consider not going to the Olympics.

The message was delivered in a conference call involving USOC officials and leaders of U.S. sport federations in late January, according to two people who participated in the call.

Federations were told that no one should go to Brazil “if they don’t feel comfortable going. Bottom line,” said Donald Anthony, president and board chairman of USA Fencing.

The USOC’s briefing to sport federations is the latest sign that Olympics officials are taking the Zika threat to the games in Rio de Janeiro seriously, and acknowledging that at least some athletes and support staff could face a tough decision over whether to attend.

The principle danger related to Zika is the potential for birth defects in babies exposed to the virus before birth, so pregnant women have particular cause for concern. The virus — which has been reported in 33 countries, mostly in the Americas, according to Reuters — has hit Brazil particularly hard, causing as many as 4,000 cases of microcephaly in newborns but had a less dramatic impact on Rio de Janeiro.

On one hand, the USOC’s reported warning hardly projects dire worry. They’re merely telling people worried about the virus to think about acting on that worry, not advising anyone to change their plans. It’s like telling someone who’s afraid of flying to consider staying home for vacation.

From Reuters:

Will Connell, Director of Sport at the U.S. Equestrian Federation, said the USOC was leaving the decision up to individual athletes and staff members.

“They said no one who has reasons to be concerned should feel obliged to go,” Connell said. “If an athlete feels that way, of course they may decide not to go.”

During the call, the USOC did not indicate they were concerned that large numbers of athletes would avoid Rio or that Zika could derail the Games, the two federation leaders said.

Instead, officials expressed optimism that risk would be minimized by close cooperation among health agencies, mosquito control efforts and the Games’ timing during Brazil’s winter when mosquito-borne illnesses are less common.

Then again, the fact that the committee felt compelled to say anything at all seems to indicate it is taking the outbreak seriously.

We’ll see in coming months if Zika has any actual effect on who ends up going to the Olympics.

About Alex Putterman

Alex is a writer and editor for The Comeback and Awful Announcing. He has written for The Atlantic, VICE Sports, MLB.com, SI.com and more. He is a proud alum of Northwestern University and The Daily Northwestern. You can find him on Twitter @AlexPutterman.